A process cartridge for an imaging device can be detachably installed within a main body of the imaging device and, as a whole unit, comprises a photosensitive assembly and at least one processing means such as charging means, developing means, cleaning means, or the like. The cartridge is detachably installed within the main body of the imaging device for convenience of maintenance. An electrophotographic imaging device functions in the following manner: an electrostatic latent image is formed by selectively exposing the electrophotographic photosensitive assembly which is uniformly charged by a charger under light from the imaging device; the electrostatic latent image is developed with a developing means using a toner into a toner image; the toner image thus formed is transferred onto a recording medium by a transferring means to form an image on a recording material.
Generally, a photosensitive drum driving assembly is provided at one end of the cartridge for receiving a driving force from the imaging device. A conventional cartridge uses a universal joint driving head connection structure for its photosensitive drum. When the cartridge is taken out of the imaging device, the universal joint driving head is leaned and removed from a driving head of the imaging device. This connection structure has a disadvantage that the universal joint driving head is prone to be stuck with the driving head of the imaging device when the cartridge is taken out of the imaging device. As a result, the process cartridge cannot be conveniently removed from the imaging device.